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S31.12AA vs S31.6

S31.12AA (Laceration with foreign body of abdominal wall unspecified flank without penetration into peritoneal cavity, initial encounter) compared with S31.6 (Open wound of abdominal wall with penetration into peritoneal cavity), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

These codes can be reported together when both conditions are documented, because S31.12AA lists S31.6 under Excludes2, which marks them as distinct conditions.

Official rule
What is different?

The conditions named and billing status.S31.12AA is “Laceration with foreign body of abdominal wall unspecified flank without penetration into peritoneal cavity, initial encounter”; S31.6 is “Open wound of abdominal wall with penetration into peritoneal cavity”. S31.6 is a non-billable header; S31.12AA is billable.

Registry fact

Can these codes be reported together?

Yes, when both are documented.S31.12AA lists S31.6 under Excludes2: “open wound of abdominal wall with penetration into peritoneal cavity (S31.6-)”. Excludes2 marks distinct conditions that may both be reported when both are documented.

Official ruleGuide: Excludes1 vs Excludes2

Is there an Excludes2 relationship?

Yes.S31.12AA’s tabular entry: “open wound of abdominal wall with penetration into peritoneal cavity (S31.6-)”. The note covers S31.6.

Official ruleGuide: Excludes1 vs Excludes2

Is one more specific?

Yes.S31.6’s title names the condition; S31.12AA’s title is the unspecified form (“Laceration with foreign body of abdominal wall unspecified flank without penetration into peritoneal cavity, initial encounter”).

MedCoder-derivedGuide: Other vs unspecified (NEC vs NOS)

Is one a parent or header code?

One is a header.S31.6 is a non-billable header, but S31.12AA is not one of its subdivisions.

Registry fact

Nothing found in 3 other checks
Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code. S31.12AA carries 1 Excludes1 note and S31.6 carries 1 Excludes1 note covering other codes; the side-by-side table quotes them.

Official rule

Are there sequencing instructions?

None.Neither entry carries a Code First or Use Additional Code note that names the other.

Official rule

Are there other coding relationships?

None found.No laterality, encounter-phase, Table of Neoplasms, Table of Drugs and Chemicals, or history-versus-active-disease relationship links these codes.

MedCoder-derived

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Excludes2 relationship

S31.12AA
Laceration with foreign body of abdominal wall unspecified flank without penetration into peritoneal cavity, initial encounter
↔
S31.6
Open wound of abdominal wall with penetration into peritoneal cavity

What we found

Yes, when both are documented.S31.12AA carries an Excludes2 note covering S31.6: “open wound of abdominal wall with penetration into peritoneal cavity (S31.6-)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

What to review

Report both only when the documentation supports both conditions; otherwise report the one documented.

Guide: Excludes1 vs Excludes2Check these on a claim

Why it matters

An Excludes2 note means the excluded condition is not part of the code above it, but a patient can have both. Report both when both are documented.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.12.b — Excludes2 · applies to: Excludes2

    A type 2 Excludes note represents “Not included here.” An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
S31.12AA

Laceration with foreign body of abdominal wall unspecified flank without penetration into peritoneal cavity, initial encounter

S31.6

Open wound of abdominal wall with penetration into peritoneal cavity

StatusDiffers
S31.12AA
Billable
S31.6
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: S31.600A, S31.600D, S31.600S, S31.601A, S31.601D

Excludes1Same for both
  • traumatic amputation of part of abdomen, lower back and pelvis (S38.2-, S38.3)
Excludes2Differs
Only at S31.12AA
  • open wound of abdominal wall with penetration into peritoneal cavity (S31.6-)
Only at S31.6

No note of its own beyond the shared notes

Shared by both codes (8 notes)
  • open wound of hip (S71.00-S71.02)
  • open fracture of pelvis (S32.1--S32.9 with 7th character B)
  • burns and corrosions (T20-T32)
  • effects of foreign body in anus and rectum (T18.5)
  • effects of foreign body in genitourinary tract (T19.-)
  • effects of foreign body in stomach, small intestine and colon (T18.2-T18.4)
  • frostbite (T33-T34)
  • insect bite or sting, venomous (T63.4)
Code alsoSame for both
  • any associated:
  • spinal cord injury (S24.0, S24.1-, S34.0-, S34.1-)
  • wound infection
CategorySame for both

S31 Open wound of abdomen, lower back, pelvis and external genitals

ChapterSame for both

S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)

IncludesDiffers
Only at S31.12AA
  • Laceration with foreign body of abdominal wall of flank NOS without penetration into peritoneal cavity
Only at S31.6

No note of its own beyond the shared notes

Shared by both codes (6 notes)
  • injuries to the abdominal wall
  • injuries to the anus
  • injuries to the buttock
  • injuries to the external genitalia
  • injuries to the flank
  • injuries to the groin
7th characterSame for both
  • The appropriate 7th character is to be added to each code from category S31

No Code first and Use additional code note at either code.

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on. In a row that differs, each code’s own notes are listed under it, and the notes every code shares are listed once beneath them.

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Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources